The fish described here is from the Madongshan Formation, Liupanshan group (Early Cretaceous), Tongxin County, Ningxia Autonomous Region, China. It is assigned to Osteoglossomorpha because it has the following synapomorphies of the superorder: a full neural spine on the first preural centrum, a primary bite between parasphenoid and basihyal, and absence of a supraorbital. This fish differs from other osteoglossomorphs in having a very short premaxilla with only three teeth, of which one is exceptionally large, and an unusual caudal skeletal in which hypural 1 is fused to the first ural centrum and hypural 2 remains autogenous. A new name is proposed, Xixiaichthys tongxinensis gen. et sp. nov., based on the unique characters and a combination of other characters. The results of the phylogenetic analysis show that Xixiaichthys is the sister group of the Osteoglossiformes ([[Notopterus Osteoglossum] [Huashia Kuntulunia]]). Therefore, the new genus is referred to Osteoglossiformes.

A new taxon of pycnodont fishes, Hensodon, is described on the basis of a well-preserved and articulated skeleton from the Cenomanian limestones of Hakel, Lebanon. A single species, Hensodon spinosus (Hennig, 1907), is assigned to the new genus. Hensodon is placed within Coccodontidae and is sister to Trewavasia. Features of Hensodon are: three massive, paired parietal and postparietal spines; a well-developed dorsal prominence rising to a high and distinct spinose apex, with the leading edge being straight and covered by a series of nuchal plates; two styliform dentalosplenial teeth and knoblike molariform prearticular and vomerine teeth; styliform branchial teeth; peltate squamation with only eight scale rows; and pelvic and anal fins preceded by strong and accentuated spines. The similar pycnodont Trewavasia differs in the presence of a single paired parietal spine, dorsal prominence without apical spines, loricate squamation pattern, scales with horizontal keels ending in a posterior spine, a dermal plate on the anterior ventral body part, no ventral apex, and a considerably higher number of hypurals. The phylogeny of pycnodonts is discussed and the paleobiogeographic patterns of Lebanese pycnodonts are reviewed.

Microposaurus casei, a poorly known temnospondyl from Subzone B of the Cynognathus Assemblage Zone (Middle Triassic) of the Karoo of South Africa, is redescribed in detail following additional preparation of the holotype skull. New and previously misinterpreted aspects of the skull roof, palate, and occiput are described, revealing an unusual skull morphology and a suite of autapomorphies. Contrary to some previous interpretations, M. casei is unequivocally shown to be a member of the stereospondyl group Trematosauroidea, as it shares a number of synapomorphies of that group. Within the Trematosauroidea, M. casei most closely resembles the slightly older, Laurasian platystegids Inflectosaurus and Platystega.

A Ctenochasma specimen from the latest Jurassic of eastern France is described in detail and referred to Ctenochasma sp. The preserved braincase of this specimen has a bird-like lateral position of the optic lobes, with proportionally a smaller size than in birds, the bones surrounding it being thick and hollow.

An original biometric analysis, based on skull length and tooth number, has been performed using a selection of Late Jurassic Pterodactyloidea of Europe. This study suggests that Ctenochasma gracile and Ctenochasma porocristata are senior synonyms of Pterodactylus elegans and Pterodactylus antiquus of Pterodactylus kochi. It also reveals that Pterodactylus elegans may be transferred to Ctenochasma. These results obtained with biometric analyses are confirmed by morphological observations. This study could not determine if Pterodactylus micronyx is a juvenile of C. roemeri, the Ctenochasma of Saint Dizier or Gnathosaurus subulatus. Because this species is only composed of juveniles, more data are needed to determine its adult morphology. The genus Ctenochasma is thus represented by three species, C. elegans, C. roemeri and C. sp., and Pterodactylus by two, P. antiquus and P. longicollum, all from the Late Jurassic of Germany and France. This study points out a biological anomaly: all the teeth are not present in a hatching pterosaur, but their number increase progressively during growth, with new teeth erupting from the front of the jaws. This phenomenon is particularly spectacular in Ctenochasma elegans, where the tooth number increases progressively from 60 to more than 400 teeth during growth.

Histological evidence of the bones of pterosaurs and dinosaurs indicates that the typically large forms of these groups grew at rates more comparable to those of birds and mammals than to those of other living reptiles. However, Scutellosaurus, a small, bipedal, basal thyreophoran ornithischian dinosaur of the Early Jurassic, shows histological features in its skeletal tissues that suggest relatively lower growth rates than in those of larger dinosaurs. In these respects Scutellosaurus, like other small dinosaurs such as Orodromeus and some basal birds, is more like young, rapidly growing crocodiles than larger, more derived ornithischians (hadrosaurs) and all saurischians (sauropods and theropods). Similar patterns can be seen in small, mostly basal pterosaurs such as Eudimorphodon and Rhamphorhynchus. However, superficial similarities to crocodile bone growth belie some important differences, which are most usefully interpreted in phylogenetic and ontogenetic contexts. Large size evolved secondarily in several dinosaurian and pterosaurian lineages. We hypothesize that this larger size was made possible by rapid growth strategies that are reflected by characteristic highly vascularized fibro-lamellar bone tissues that comprise most of the cortex. Dinosaurs and pterosaurs, like other tetrapods, generally grew more quickly in early stages and more slowly as growth neared completion. As in other vertebrate groups, taxa of small adult size may have grown at lower rates or for shorter durations than larger taxa did. Phylogenetic patterns suggest that by themselves, the low vascularity and inferred low growth rates seen in small dinosaurs and pterosaurs are not good indicators of thermometabolic regime, because they are correlated so strongly with size. They may reflect mechanical exigencies of small size rather than especially lower growth rates, tied to the process of deposition of particular kinds of bone tissues. The evolution of life history strategies in dinosaurs and pterosaurs, as they relate to rates of growth and adult body sizes, will be better understood as more complete histological studies place these data into phylogenetic and ontogenetic contexts.

A new basal neoceratopsian genus and species, Prenoceratops pieganensis, is described from the Two Medicine Formation of Montana. This material represents the only bone-bed deposition of a basal neoceratopsian currently known, and in addition is almost entirely disarticulated allowing for a more thorough understanding of basal neoceratopsian cranial morphology. The new taxon is characterized by a lower, more sloping head than in Leptoceratops, with a nasal that is pinched caudally, a wide, triangular jugal, extremely gracile surangular, and reduced articular among other autapomorphies. A preliminary cladistic analysis unites Prenoceratops firmly with the other North American basal neoceratopsians (and one Asian taxon) in the clade Leptoceratopsidae.

The cranial anatomy of ceratopsian (“horned”) dinosaurs is well understood, but the postcranial skeleton has been largely ignored in previous studies of phylogeny, evolution, and function. In order to study morphological differences among ceratopsian postcranial elements and to compare evolutionary patterns, multivariate (Principal Components Analysis) and bivariate methods were used to analyze linear measurement data, and the shape methods Resistant-Fit Theta-Rho Analysis (RFTRA), Least-Squares Theta-Rho Analysis (LSTRA), and Euclidean Distance Matrix Analysis (EDMA) were applied to biological landmark data. Results of the analyses show that size is the primary change through ceratopsian skeleton evolution. Elements display positive allometry, and increasing structural support is evident, especially in the radius and fibula.

Phylogenetic distribution of ceratopsian postcrania agrees with the skull material included in recent cladistic analyses. Psittacosaurus elements are in many ways derived relative to those of non-ceratopsid neoceratopsians, and evidence suggests that Psittacosaurus was bipedal, while non-ceratopsid neoceratopsians were not, except maybe for Udanoceratops. With increasing body size, neoceratopsian limbs bowed laterally.

The variety of methods allows for unbiased interpretation of results, provides more information than any one method, and provides controls for each other. However, sample sizes are not ideal, and all results should be treated with caution at this time.

Eothoracosaurus mississippiensis, gen. et sp. nov., is based on a skull and partial skeleton from the Upper Cretaceous (early Maastrichtian) Ripley Formation of Mississippi. Less complete material from the late Campanian or early Maastrichtian of western Tennessee is referred to this taxon. It can be distinguished from late Maastrichtian Thoracosaurus neocesariensis on the basis of a wider distance between the supratemporal fenestrae, a long anterior frontal process, and closer apposition of the third and fourth dentary alveoli. Longirostrine crocodylian remains from the later Maastrichtian and earliest Paleocene of New Jersey pertain to a single species (Thoracosaurus neocesariensis), as do remains from the early Paleocene of France and Sweden (Thoracosaurus macrorhynchus). The basisphenoid in these animals is still an anteroposteriorly thin lamina wedged between the basioccipital and pterygoid, reflecting the “verticalized” condition seen in extant non-gavialoid crocodylians. At least some late Paleocene occurrences from New Jersey, Maryland, and Virginia can be referred to Thecachampsoides minor (Marsh, 1870), and a second larger gavialoid may also be present in these units. North American “thoracosaurs” lacked antorbital fenestrae. “Thoracosaurinae” are a para-phyletic grade at the base of Gavialoidea, with Thecachampsoides being closer to Gavialis than are Thoracosaurus or Eothoracosaurus. Prior referral of “thoracosaurs” to Tomistominae reflects a typological approach to taxonomy, with longirostrine crocodylians maintaining plesiomorphic rostral states being regarded as tomistomines.

The bone histology of gorgonopsian, therocephalian and cynodont genera, ranging from the Late Permian to Early Jurassic, was examined. The analysis reveals a predominance of cortical fibrolamellar bone tissue in most skeletal elements. The high prevalence of fibrolamellar bone tissue suggests an overall rapid osteogenesis, but interruptions in the form of annuli and/or LAGs do occur. Inter-elemental histovariation within individuals, such as primary tissue type, cortical porosity, LAGs and annuli, extent of secondary reconstruction and endosteal bone deposition, is observed. In general, propodials were found to have grown faster than epipodials. Distinct growth patterns were identified for each of the genera studied. These growth patterns vary from a cyclical growth pattern in the Late Permian gorgonopsian, Scylacops to fast, sustained growth in the Early Jurassic cynodont, Tritylodon. Growth patterns of contemporaneous genera are also noted and discussed. A possible trend towards fast growth, and an independent decrease or eventual loss of developmental plasticity within the therapsids, is proposed.

A new tritylodontid cynodont, Bienotheroides ultimus sp. nov., is described from the Upper Jurassic Shishugou Formation of Jiangjunmiao in the northeastern Junggar Basin of Xinjiang (NW China). The type consists of a partial skeleton, including teeth, a partial skull, and a considerable portion of the postcranium. It is identifiable as Bienotheroides because of the structure of the upper molars and the characteristically deep zygomatic arch. It is distinguished from Bienotheroides zigongensis from the Middle Jurassic of the Junggar Basin particularly by characters of the forelimb, including a humerus that shows little torsion of the proximal and distal ends. Bienotheroides ultimus is the last of the Chinese tritylodontids known so far, and apart from Xenocretosuchus from the Lower Cretaceous of Russia and an unnamed form from the Lower Cretaceous of Japan, it is the last non-mammalian therapsid known in the entire fossil record.

The biogeography and faunal evolution of middle to late Eocene mammals throughout East Asia is assessed. Appearance Event Ordination was used to get a reliable temporal ordination of 92 Paleogene faunas from East Asia. Results from this analysis are generally consistent with the faunal sequence of traditional East Asian Land Mammal “Ages” (EALMAs). Exceptions are that the Arshantan Fauna fell within Irdinmanhan EALMA faunas, and three latest middle to late Eocene faunas from southern East Asia are misaligned due to high degrees of endemism. Comparison of 30 major middle/late Eocene mammalian faunas at the generic level, using Simpson's Faunal Resemblance Index and the ordinal composition of each fauna indicate that: (1) the differentiation in faunal similarity and composition between northern and southern East Asia started near the middle Eocene-late Eocene boundary; (2) this differentiation is reflected by the decline of perissodactyls and radiation of several artiodactyl clades in the later Eocene of southern East Asia; and (3) in southern East Asia, faunal endemism increased in the later Eocene. The latest middle to late Eocene faunas of the southern area do not fit within the EALMA system, which was primarily established with northern faunas, because of their endemism. Mammalian faunal changes actually seem to have begun much earlier in the southern region of East Asia than in the northern part, so the faunal changes toward the end of the Eocene in East Asia were not synchronous. Faunal changes during the Eocene-Oligocene transition in southern East Asia seem not to have been controlled by global climatic changes.

Nambaroo bullockensis sp. nov. is a structurally primitive macropodoid from the Bullock Creek Local Fauna of the Camfield Beds of the Northern Territory, Australia. This species extends the range of Nambaroo from the late Oligocene or early Miocene up to the middle Miocene. Despite its young age, N. bullockensis retains many features thought to be plesiomorphic for macropodoids. Cladistic analysis based on characters of m1 for this new species and all other balbarines shows Nambaroo to be paraphyletic, but supports the monophyly of Ganawamaya and Balbaroo.

A new species of Sayimys (Ctenodactylidae, Mammalia), Sayimys giganteus sp. nov., is described from the Early Miocene localities of Keseköy 1, Keseköy 2, and Hisarcik (Turkey). Sayimys giganteus sp. nov. differs from other known species of Sayimys by its larger size and several plesiomorphies (e.g., metalophulid II on dp4, strong anterolophid and posterolophid on P4, and a long paraflexus and metaflexus on upper molars), but also in the presence of some derived characters. Two species of Sayimys are currently recognized in Turkey: Sayimys cf. Sayimys intermedius (at Paşalar, Middle Miocene) and Sayimys giganteus sp. nov. Based on a cladistic analysis involving all known species of Sayimys, Metasayimys, and Prosayimys, Sayimys giganteus sp. nov. emerges as the sister taxon of Sayimys obliquidens.

Lycopsis longirostris, a middle Miocene Colombian borhyaenoid, is compared functionally with early Miocene borhyaenoids from Patagonia and the Tasmanian thylacine Thylacinus cynocephalus, the largest Recent marsupial carnivore. The postcranium of Lycopsis shows a mosaic of features. Although several features characterizing the long bones are consistent with a primarily terrestrial mode of life (e.g., a straight ulna and tibia, a semi-digitigrade forefoot), other features like the development of mm. spinati, pectoralis and biceps and the pseudo-opposable pollex indicate that the forelimb had manipulative and grasping abilities. On the hindlimb, the poorly stabilized lower ankle joint, the short metatarsals, and the well-developed hallux also preclude fast running. When compared to three early Miocene borhyaenoids, Prothylacinus patagonicus, Cladosictis patagonica, and Borhyaena tuberata, which form a morphological gradient from the most arboreally-adapted taxon to an incipient cursorial one, Lycopsis is placed between Cladosictis and Borhyaena. Lycopsis was more likely an ambush hunter than a pounce-pursuit predator, stalking small-to medium-sized prey.

The mesocarnivorous procyonine genera Bassariscus and Probassariscus first appear in the early Barstovian, when they are represented by four species. Bassariscus antiquus is known from the Olcott Formation of Nebraska, B. cf. parvus from the Skull Ridge Member of the Tesuque Formation of New Mexico, and B. minimus, sp. nov., from the Olcott Formation and Observation Quarry in Nebraska. Probassariscus is restricted to the single species P. matthewi from the Virgin Valley Formation of Nevada, Observation Quarry of Nebraska, and possibly the Flemming Formation of Texas. The subfamily Procyoninae is divided into two tribes, Potosini and Procyonini. The procyonin Probassariscus is more closely related to Procyon and Nasua than to Bassariscus. Based on dental characteristics, Bassariscus is the most primitive genus of the Procyonini.

Promephitis is a widespread late Tertiary Eurasian skunk in the family Mephitidae (Carnivora, Musteloidea), but many of the currently-recognized nine species were established on isolated dental material. Recent discoveries of Promephitis comprised of numerous nearly perfectly preserved skulls and jaws from Gansu Province, China, together with material from other Chinese localities plus unpublished material in the Frick Collection, make the Chinese record of Promephitis unrivaled in terms of quality, quantity, and species diversity.

Four species of Promephitis are present in the Baodean land mammal age of East Asia: Promephitis parvus, sp. nov., from Hezheng region of Gansu Province; Promephitis qinensis, sp nov., from Fugu area of Shaanxi Province; Promephitis hootoni, the most common Chinese species; and Promephitis alexejewi from the terminal Miocene locality of Ertemte, which is still poorly known. Promephitis parvus represents the smallest known species of the genus and is also the most primitive in cranial and dental morphologies. Promephitis qinensis is a transitional form that may have given rise to P. hootoni. If so, the Turkish occurrence of P. hootoni must be the result of westward expansion of its range.

An exceptionally well-preserved skull and associated dentary from the Chiquimil locality in the Andalhuala Formation (Huayquerian Age, late Miocene), Santa María Basin, Catamarca Province, northwestern Argentina, represent a new giant porcupine, Neosteiromys pattoni, sp. nov. N. pattoni is derived relative to Neosteiromys bombifrons Rovereto, 1914, the type species of the genus, by having pentalophodont m2–m3, a markedly infected angular region, more prominent masseteric crest, deeper masseteric fossa, and larger auditory bullae. Both species of Neosteiromys appear to have been adapted to eat harder, more abrasive food items than those consumed by extant porcupines, as inferred from their stronger masticatory apparatus. They may have inhabited more open environments than those of living Neotropical porcupines.